#box_container {
    width: 100px;
    height: 100px;
    background-color: blue;
    overflow: auto;
}

#box {
    padding: 10px;
    margin: 10px;
    border: solid 10px red;
    background-color: yellow;
}

#content {
    width: 40px;
    height: 40px;
    background-color: green;
}